A vital part of the licensing process for advanced (non-LWR) nuclear reactor developers in the United States is the assessment of the reactor’s source term. The source term represents the potential release of radionuclides from the reactor system to the environment during normal operations or accident sequences. While historically source term assessment for LWRs has followed a bounding approach with conservative assumptions, a more mechanistic, or realistic, approach to modeling radionuclide transport is being used for advanced reactor systems. As the designs of advanced reactors increase in maturity and move towards licensing, there will be a need to develop modeling and simulation capabilities in analyzing the source term of a prospective reactor concept.
Two types of fast spectrum advanced reactors currently being pursued are liquid metal-cooled fast reactors and fast-spectrum molten salt reactors. The sodium fast reactor (SFR) is the most pursued variant of the liquid-metal cooled reactors, while there is also interest in lead-cooled fast reactors (LFR), which share much of the same source term modeling phenomena. Among salt-fueled molten salt reactors (MSR), there is interest in both chloride salt (Molten Chloride Fast Reactor, MCFR) or fluoride salt (Molten Salt Fast Reactor, MSFR) as the fuel-bearing salt system. There has been much work in the development of the mechanistic source term for SFRs due to the extensive operational experience in the U.S. MSR technology is generally less mature and there is more diversity in the designs being pursued, therefore the development of source term strategies is largely incomplete at present.
This work is meant to be a summary of the phenomena important to modeling the mechanistic source term of both SFRs and MSRs, the functional requirements needed to model those phenomena, and the current state of computational capabilities in fulfilling those requirements. In completing a survey of the current landscape of modeling capabilities with a gap analysis, this work aims to identify the future modeling and simulation development needs.
|Speaker's email firstname.lastname@example.org|
|Country/Int. organization||United States of America|
|Affiliation/Organization||Argonne National Laboratory|